1. Field of the Invention
This invention relates generally to telecommunications, and more particularly, to wireless communications.
2. Description of the Related Art
The rise of Internet has resulted in a trend that demands more and more services, such as Internet protocol (IP)-based services by mobile users. However, a universal mobile telecommunication system (UMTS) terrestrial radio access network (UTRAN) is unable to satisfy this demand efficiently because UTRAN has inherited a centralized network architecture with a quite complex central radio network controller (RNC) and simple base stations (e.g., a base transceiver station (BTS) called “Node B” in UMTS) from global system for mobile communications (GSM)—a land mobile pan-European digital cellular radio communications system. Therefore, to cope efficiently with an expected growth of data communication and to exploit the full scope of IP applications, some further modifications to the centralized network architecture for the UMTS radio access network, as defined in Rel.5, may be needed.
However, the centralized network architecture offers such features which are not that useful in an IP network architecture. For example, the centralized network architecture is strictly hierarchical. The centralized network architecture contains a core network (CN), represented by serving global packet radio service (GPRS) support node (SGSN) that performs mobility and data session management for GPRS mobiles is the highest level, followed by a RNC, which distributes the traffic to the respective Node B. In the centralized network architecture, the main intelligence of the UTRAN is concentrated within the RNC.
As a central instance, a RNC manages the provisioning of all necessary bearer services for control and user traffic in order to establish a radio access bearer (RAB) between user equipment (UE) and a CN. This centralized network architecture for GSM provides wireless access to a circuit-switched (CS); voice-oriented telecommunications network, such as a public switched telecommunications network (PSTN). Thus, the transport network topology of the centralized network architecture pursues this hierarchy and is a star or a tree shaped. Instead, the IP network architecture is logically fully meshed and hides its physical topology from the transport mechanism itself.
Although the centralized network architecture has been since extended to packet data services, such as GPRS, but the rise of the Internet and its different service requirements have not been addressed adequately. Even if IP transport may replace Asynchronous Transfer Mode (ATM)-based links between a RNC and a Node B, a full advantage of the IP transport may not be realized because of characteristics of various interfaces that involve carrying synchronized radio link blocks with a high quality of service, regardless of a user service to which they belong.
Specifically, to manage mobility of several users within a given group of access nodes (e.g. micro-mobility within a location or a routing area), in the centralized network architecture, a central node keeps track of any user or UE, such as a wireless communication device within its administrational area. In order to allow a quick locating of a specific UE, the name (i.e. node identification (ID)) of this central node is reported to a home location register (HLR) of the UE; regardless if the UE is in its home public land mobile network (H-PLMN) or visited PLMN (V-PLMN). If the administrational area is small, for instance, only composed of a single access point, this may happen quite frequently and will therefore cause heavy signaling traffic. Such heavy signaling traffic is one of the main obstacles to decentralize a hierarchical mobile communication system architecture.
One aspect from a network operator's point of view is a multi-vendor environment and not a supplier specific solution, resulting in a minimal impact on existing standards while avoiding interchangeability of network elements. Although different solutions involving a decentralized approach for the above mentioned problem have been suggested, but most of these approaches propose modifications in many existing standards or changes in a system implementation at a significant expense of cost and deployment effort.
The present invention is directed to overcoming, or at least reducing, the effects of, one or more of the problems set forth above.